Mirror positioning apparatus for use in beam switching

ABSTRACT

A mirror positioning assembly for use in beam switching is provided that employs a novel arrangement of the mirrors and the motors to selectively position the mirrors. The assembly is installed into the housing of an assembly for distributing laser energy where the mirrors are contained within the beam cavity and the remainder of the assembly is outside of the housing. The assembly is received in a port within the housing in a manner that allows 360° of rotational adjustment so that the mirror can be carefully aligned to insure near lossless distribution of the beam energy as it passes through the device. This arrangement keeps the electronics, motors, bearings and adjustments of the mirror switching external to the beam cavity herby reducing the number of potential contaminants contained therein.

BACKGROUND OF THE INVENTION

The present disclosure relates generally to an apparatus for selectivelydistributing a laser beam from a single laser source to one of aplurality of outputs. More specifically, the present disclosure relatesto a sealed apparatus through which laser energy from a single source isdirected in a manner that selectively distributes the laser energy toone of a plurality of outputs while protecting the distribution elementscontained therein from contamination.

Laser technology has developed greatly over the past few decades in amanner that finds lasers being used in a multitude of environments toaccomplish a great number of tasks. Some well-known processes for whichlasers are being employed include telecommunications, machining of toolsand parts and medical procedures. Further, the number of applications inwhich lasers are employed continues to increase as the power level ofthe available lasers increases. As the power level of the energy beingtransmitted along the fiber increases, such as laser energy employed inmedical treatment and diagnosis, the need for precise, the need toprovide low loss coupling greatly increases. Further, such couplers mustoften aggregate energy from multiple conduits into a single transmissionfiber or distribute the energy from a single laser source to one or aplurality of outputs.

There are now a number of high-power single-mode fiber lasers havingoutput power in the range of 1-50 kW that are coming into widespread usein the industrial fields of welding, high-speed cutting, brazing, anddrilling. Such fiber lasers have high wall plug power efficiency andvery good beam characteristics. The beam from these fiber lasers can befocused to small spot sizes with long focal length lenses withconsistent beam properties independent of power level or pulse duration.Ytterbium single-mode fiber lasers with an M² of 1.1 have continuallyincreased in power to the multi-kW level, and can be focused to 10-15 μmspot diameters with perfect Gaussian distribution. Further increasingpower will open up additional markets in the future.

One of the difficulties that has arisen is that as the power of thelaser energy that must be distributed increases, the difficulty relatingto the distribution of that energy also greatly increases. Thesedistribution systems must be robust and capable of handling the wasteheat generated through the distribution of the laser energy. Further,the devices must provide a very stable platform onto which all of thevarious components are installed to insure correct alignment of thevarious input and output ports to prevent losses resulting from poorlyaligned components.

In the prior art, such distribution systems are typically built on alarge and heavy slab of metal that serves as a base platform to whichthe other components are mounted. In addition to the various switchingmirrors used to distribute the laser energy, motors for moving themirrors, electrical wiring and coolant conduits are all installed on theplatform. Once assembled, a cover is then placed over the top of theplatform to protect all of the elements contained thereon. Thisarrangement, however, creates problems of its own in that all of thecomponents are contained within the same cavity through which the laserenergy is distributed. The heat generated by the laser energy istransferred into the various other components contained within the beamcavity. As the wires, pipes and motor windings are heated, they off gascoating all of the components within the beam cavity including theswitching mirrors and optics with a film that obscures these opticalelements resulting is energy loss during distribution operations. Inaddition, operation of the motors causes dust to be emitted that canalso settle onto the optical elements. Further, should any componentwithin the beam cavity fail or require servicing, the entire device mustbe shut down so that the cover can be removed to allow access to thecomponents contained therein.

Therefore, there is a need for an apparatus that can selectivelydistribute a laser beam from a single laser source to one of a pluralityof outputs.

There is a further need for a reduced size, sealed apparatus throughwhich laser energy from a single source is directed in a manner thatselectively distributes the laser energy to one of a plurality ofoutputs while protecting the distribution elements contained thereinfrom contamination.

Still further there is a need for an apparatus for distributing laserenergy that is compact and modular in nature while providing a sealedbeam cavity that protects the optics contained therein from thecontamination issues encountered in the prior art.

Yet there is a further need for an apparatus for distributing laserenergy configured with reflective components witch are contained withinthe housing of apparatus, whereas the remainder of the apparatus isoutside of the housing yet supported in a manner that allows 360° ofrotational adjustment to facilitate carefully alignment of thereflective components.

BRIEF SUMMARY OF THE DISCLOSURE

In this regard, the present disclosure provides for an apparatus forselectively distributing a laser beam. The apparatus can be employed fordistributing laser energy from a single laser source to one of aplurality of outputs or from a plurality of laser sources to a singleoutput. More specifically, the present disclosure relates to a sealedapparatus through which laser energy from a single source is directed ina manner that selectively distributes the laser energy while protectingthe distribution elements contained therein from contamination.

Generally, in the context of the present disclosure, an assembly fordistributing laser energy is provided with a compact rigid housing witha sealed beam path contained therein. Other than the optics and mirrorcomponents required selectively direct the beam energy, there are noelements of the distribution device contained within the beam path. Thisarrangement allows for compact and reliable beam distribution whilegreatly reducing the possibility of contaminating the optics within thebeam path.

In one embodiment, the present disclosure operates to distributeincoming energy from a single source to one or more outputs. In thisembodiment, an input port is provided at one end of the housing suchthat the laser energy is directed into a beam path within the housing.Along one side of the housing, two or more output ports are provided towhich the beam energy is to be selectively distributed. Opposite theoutput ports, selectively positionable mirrors are provided that areoperable between an in-beam and an out-of-beam position to selectivelydirect the energy from the input source to the desired output. Inaddition, in the scope of the present disclosure it is possible that themirrors are coated in a manner that allows a portion of the beam energyto pass therethrough even when the in-beam position such that the deviceof the present disclosure operates as a beam sharer.

In another embodiment, the present disclosure operates as a beamcombiner to direct energy from one or more sources to a single output.While the assembly is the same as in the embodiment above, the sourceenergy is now coupled to the ports on the side of the housing and thedesired output is coupled to the end of the housing. In this embodiment,the selectively positionable mirrors are preferably one-way mirrorsallowing energy that impacts the rear of the mirror to passtherethrough.

An important feature of the present disclosure is the arrangement of themirrors and the motors used to selectively position the mirrors. Whilethe mirrors are contained within the beam cavity, the remainder of theassembly is outside of the housing. The assembly is received in a portwithin the housing in a manner that allows 360° of rotational adjustmentso that the mirror can be carefully aligned to insure near losslessdistribution of the beam energy as it passes through the device. Thisarrangement keeps the electronics, motors, bearings and adjustments ofthe mirror switching external to the beam cavity herby reducing thenumber of potential contaminants contained therein.

These and other features of the disclosure are pointed out withparticularity in the claims annexed hereto. For a better understandingof the disclosure, its operating advantages and the specific objectsattained by its uses, reference should be had to the accompanyingdrawings and descriptive matter in which there is illustrated apreferred embodiment of the disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings which illustrate the best mode presently contemplatedfor carrying out the present disclosure:

FIG. 1 is a perspective view of the apparatus of the present disclosurefor selectively distributing a laser beam;

FIG. 2 is an exploded perspective view of the apparatus of the presentdisclosure for selectively distributing a laser beam;

FIG. 3 is a cross-sectional view taken along line 3-3 of FIG. 1;

FIG. 4 is a perspective view of the head portion of the mirrorpositioning apparatus of the present disclosure;

FIG. 5 is a cross-sectional view taken along line 5-5 of FIG. 4; and

FIG. 6 is a cross-sectional view of the head and motor of the mirrorpositioning apparatus installed into a housing.

SPECIFIC DESCRIPTION OF THE DISCLOSURE

Now referring to the drawing figures an apparatus for selectivelydistributing a laser beam is shown and illustrated. The apparatus can beemployed for distributing laser energy from a single laser source to oneof a plurality of outputs or from a plurality of laser sources to asingle output. More specifically, the present disclosure relates to asealed apparatus through which laser energy from at least one source isdirected in a manner that selectively distributes the laser energy whileprotecting the distribution elements contained therein fromcontamination.

Turning to FIG. 1, it can be seen that the assembly 10 for distributinglaser energy of the present disclosure is configured with a compactrigid housing 12. The housing 12 is monolithic with heavy wallconstruction and structured so that all of the elements installedtherein are held in a manner such that their relative positioning isprecisely maintained. As will be described in detail below, the housing12 contains a sealed beam cavity therein. In this manner, other than theoptics and mirror components required selectively direct the beamenergy, there are no elements of the distribution device containedwithin the beam cavity. This arrangement allows for compact and reliablebeam distribution while greatly reducing the possibility ofcontaminating the optics within the beam cavity.

Turning to FIGS. 2 and 3, it can be seen that the housing 12 includes asealed beam cavity 14 (FIG. 3) that is defined within the housing 12.The beam cavity 14 is the space within the housing 12 in which the laserbeam energy travels. As was noted above when numerous componentsrelating to the operation of the beam distribution apparatus 10 arecontained within the beam cavity 14, the risk of contaminating thevarious optical elements contained therein greatly increases. As aresult, it can be seen that the only elements within the beam cavity 14are the optics used in connection with the beam distribution function.In addition, there can be seen at least one input port 16 configured todirect beam energy from the laser into the beam cavity 14, at least onecontrol port 18 including a mirror 20 disposed within the beam cavity14, wherein the mirror 20 is movable between a first in-beam position(see 20′ in FIG. 3) to redirect laser energy from the at least one inputport 16 and a second out-of-beam position (see 20″ in FIG. 3) whereinthe laser energy is unaffected by the mirror 20 and at least one outputport 22 configured to receive redirected beam energy from the mirror 20in the in-beam position 20′ and direct it out of the beam cavity 14.

While in this particular illustration, there is shown one input and twooutputs, this is meant to be illustrative of a preferred embodiment andis not intended to limit the scope of this disclosure to thespecifically illustrated embodiment. Accordingly, it is possible to haveat least one input and at least one output as well as having a pluralityof inputs and/or a plurality of outputs and any combination thereof. Anysuch arrangement is intended to fall within the scope of the presentdisclosure.

A collimator 24 assembly can be seen installed into each of the input 16and output ports 22. The collimator assemblies 24 are modular inconstruction and include optics 26 therein to shape and focus the laserbeam energy as it is launched into the beam cavity 14 and as it isdistributed and relaunched using the output ports 22. Further, it can beseen that each of the collimators 24 includes a modular connector 28 onan outboard end thereof to allow easy connection of a waveguide thereto.On the input port 16 of collimator 24 a waveguide is attached using themodular connection 28, wherein the waveguide serves to provide laserbeam energy for distribution by the apparatus 10 of the presentdisclosure. Such a waveguide is preferably a fiber that extends from afiber laser but may be any other known type of waveguide for propagatingoptical energy. On the output port 22 collimator 24, waveguides areattached that serve to propagate the distributed laser energy to variousterminal devices such as tools or the like. It can be further seen thateach of the collimators 24 includes an integrated coolant path 30 (FIG.3) therein and integrated connections 32 (FIG. 2) for integration with acooling system. In this manner, the modular collimators 24 are eachcooled in a manner that keeps the cooling components out of and awayfrom the beam cavity 14.

In the housing 12 opposite the output ports 22 there can be seen atleast one control port 18 wherein the control port 18 receives a mirrorapparatus 34 for selectively distributing laser energy. While thedetails relating to the structure of the mirror apparatus 34 will bediscussed below, functionally, the mirror apparatus 34 includes a mirror20 disposed within the beam cavity 14, wherein the mirror 20 is movablebetween a first in-beam position 20′ (FIG. 3) to direct laser energyentering the apparatus 10 through the at least one input port 16 to theat least one output port 22 and a second out-of-beam position 20″wherein the laser energy is unaffected by the mirror 20.

Additionally, there can be seen a dump port 36 that is positionedopposite the input port 16. The dump port 36 is configured and arrangedto absorb the laser beam energy if all of the mirrors 20 are in theout-of-beam position 20″. This prevents the laser energy from destroyingthe housing 12 or burning the components contained within the beamcavity 14.

In one preferred embodiment the present disclosure provides for exactlyone input port 16, at least two control ports 18 and at least two outputports 22 corresponding to each of the control ports 18. Further there isa dump port 36 as described above opposite the input port 16 forabsorbing laser energy should the mirrors 20 all be positioned in theout-of-beam position 20″. By selectively moving the mirrors 20 at eachof the control ports 18, the laser energy can be redirected from theinput port 16 to either one of the corresponding output ports 22. Alsowithin the scope of this embodiment, it is possible that only the mirror20 positioned furthest from the input port 16 is fully reflective andthe remaining mirrors 20 are partially reflective such that positioningmore than one of the mirrors 20 in the in-beam position 20′ directs aportion of the laser energy to the corresponding output ports 22. Thisallows beam sharing of a portion of the beam energy at each of theoutput ports 22.

It should be appreciated by one skilled in the art that the positioningof the outputs and inputs in the preferred embodiment can be reversedsuch that at least to laser beams are directed into the output ports(which now function as input ports) and the energy is then directedthrough selective movement of the mirrors at each of the control portsto redirect laser beam energy from the to the input port (nowfunctioning as an output port). This arrangement allows energy from twodifferent lasers to be shared at one location. In this embodiment, itshould be appreciated that there needs to be at least two dump portsopposite each of the outputs (functioning as inputs) wherein the dumpports are configured and arranged to absorb the corresponding laser beamenergy when its corresponding mirror is in the out-of-beam position.Further in this embodiment the mirrors may be formed as one-way mirrorssuch that positioning more than one of the mirrors in the in-beamposition allows laser energy from a rear surface of the mirror to passtherethrough thereby directing the laser energy from each of the inputsto the output port. Such an arrangement would allow the apparatus tooperate as a beam combiner.

Turning now to FIGS. 4 and 5, the details of the mirror apparatus 34 forselectively distributing energy from a laser beam in the apparatus 10 ofthe present disclosure are shown and illustrated. The mirror apparatus34 generally includes a support plate 38 having an aperture 40 thatextends therethrough. A rotatable shaft can be seen to extend throughthe aperture 40. A mirror 20 is shown to a first end of the shaft and adrive interface 44 is affixed to a second end of the shaft. Further, abearing 46 can be seen installed in the aperture 40 and about the shaftwherein the bearing 46 serves to seal the mirror apparatus 34 to preventany fluid or contamination from passing from one side of the supportplate 38 to the other, and further serves to precisely guide rotation ofthe shaft. The housing 12 has a opening 48 which is formed with themechanical steps to limit the mirror movement.

Turning now to FIG. 6 in combination with FIGS. 4 and 5, a motor 50 canbe seen installed into the mirror apparatus 34 wherein the drive shaft52 of the motor 50 is affixed to the drive interface 44. Preferably themotor 50 is a stepper motor that serves to selectively step the mirror20 precisely between an in-beam position 20′ and an out-of-beam position20″. It is of further note that in the scope of the present disclosurethe drive interface 44 is preferably flexible such that vibrationsassociated with the operation of the motor 50 and any misalignment ofthe motor's rotation is not transferred into the shaft therebypreventing it from causing misalignment in the mirror 20 position.

The mirror apparatus 34 is received into one of the control ports 18 inthe housing 12 wherein the control port 18 is particularly configured toreceive the mirror apparatus 34 and includes a seat 54 formed thereinagainst which the mirror apparatus 34 is received. The support plate 38of the mirror apparatus 34 can be seen to include a rounded supportshoulder 56 that extends around an outer surface thereof. When in theinstalled position, the support shoulder 56 contacts the seat 54 and isconfigured and received against the seat 54 in a manner that allows theangular position of the mirror assembly 34 can be adjusted relative tothe housing 12 and ultimately the beam path. The support plate 38includes setscrews 58 therein that can be tightened or loosened in orderto adjust the angular position of the mirror assembly 34 relative to thehousing 12. This allows the beam distribution assembly 10 of the presentdisclosure to be carefully aligned and calibrated to insure a low losscoupling of the beam energy between the beam input and output ports.

Finally it can be seen that the mirror 20 is releasably secured to theshaft. This is done via any known fastening means in the art such as byusing screws 60 as shown herein. This allows replacement of the mirror20 and allows the housing 12 to be smaller in that the mirror 20 can besecured to the shaft after the support plate 38 is installed into thehousing 12.

It can therefore be seen that the present disclosure provides anapparatus that can selectively distribute a laser beam either from asingle laser source to a plurality of outputs or from a plurality ofsources to a single output via a reduced size, sealed apparatus whileprotecting the distribution elements contained therein fromcontamination. Further, a beam switch is provided for use in a laserbeam distribution assembly wherein the mirrors of the beam switch arecontained within the beam cavity and the remainder of the beam switchassembly is outside of the housing yet supported in a manner that allows360° of rotational adjustment to facilitate carefully alignment of themirror. For these reasons, the instant disclosure is believed torepresent a significant advancement in the art, which has substantialcommercial merit.

While there is shown and described herein certain specific structureembodying the disclosure, it will be manifest to those skilled in theart that various modifications and rearrangements of the parts may bemade without departing from the spirit and scope of the underlyinginventive concept and that the same is not limited to the particularforms herein shown and described except insofar as indicated by thescope of the appended claims.

1. A mirror apparatus for selectively distributing energy from at leastone laser beam comprising: a support plate with an aperturetherethrough; a rotatable shaft extending through said aperture; amirror affixed to a first end of said shaft; a motor operative to applya torque to the shaft; and a flexible drive interface located betweenand coupled to said motor and a second end of said shaft, said flexibledrive interface being configured to prevent vibrations of the motor tobe transferred into the rotatable shaft.
 2. A mirror apparatus of forselectively distributing energy from at least one laser beam comprising:a support plate with an aperture therethrough; a rotatable shaftextending through said aperture; a mirror affixed to a first end of saidshaft; a flexible drive interface affixed to a second end of said shaft;and a bearing/bushing unit in said aperture and about said shaft toprecisely guide rotation of said shaft.
 3. The mirror apparatus of claim1, wherein said motor is a stepper motor.
 4. The mirror apparatus ofclaim 1, wherein said motor selectively moves the mirror between anin-beam position and an out-of beam position.
 5. A mirror apparatus offor selectively distributing energy from at least one laser beamcomprising: a support plate with an aperture therethrough; a rotatableshaft extending through said aperture; a mirror affixed to a first endof said shaft; a flexible drive interface affixed to a second end ofsaid shaft; and a coolant path integrated within the apparatus.
 6. Themirror apparatus of claim 5 further comprising: a housing having acontrol port therein for receiving said mirror apparatus, said controlport including a seat formed therein, wherein the support plate of themirror apparatus includes a rounded support shoulder extending around anouter surface thereof, said support shoulder contacting said seat whensaid mirror apparatus is received in said control port such that anangular position of said mirror apparatus can be adjusted relative tosaid housing.
 7. The mirror apparatus of claim 6, wherein the supportplate includes set screws therein to adjust the angular position of saidmirror apparatus can be adjusted relative to said housing.
 8. The mirrorapparatus of claim 6, wherein said minor is releasably secured to saidshaft.
 9. The mirror apparatus of claim 8, wherein said mirror issecured to said shaft after the support plate is installed into saidhousing.
 10. The mirror apparatus of claim 6, wherein said housingcontains a beam cavity therein, said mirror being positioned within saidbeam cavity and said motor being external to said beam cavity.